TMCC2 and breast cancer: However, among all the erythroid cell types, the most primitive erythroid progenitors (GATA1high) originated overwhelmingly in the non-responder P03 and the fast-BC-transforming patient P04 at diagnosis (Ery-TMCC2+ from P03-BT and Ery-CA2+ from P04-BT, Figure 3A, 3B).